How Do Corticosteroids Work?

Reviewed on 1/10/2022


Corticosteroids also known as “steroids” are a class of drugs that are synthetic analogs of steroid hormones which are naturally produced by the outer portion of the adrenal glands (two small glands located on top of the kidney) known as the cortex. Corticosteroids are anti-inflammatory medicines that work by reducing the activity of the immune system and are used for a wide range of conditions including rheumatologic diseases such as rheumatoid arthritis, lupus or vasculitis (inflammation of the blood vessels), asthma, allergies, and skin conditions (insect bites, poison oak/ivy, eczemadermatitis, allergies, rash, itching of the outer female genitals, anal itching). 

They are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior. 

Corticosteroids are classified as either:

  • Glucocorticoids (anti-inflammatory)-suppress inflammation and immunity and assist in the breakdown of fats, carbohydrates, and proteins
  • Mineralocorticoids (salt retaining)-regulate the balance of salt and water in the body

Corticosteroids are available in different forms including:

  • Tablets (oral steroids)
  • Injections–which can be administered into blood vessels, joints, or muscles
  • Inhalers–mouth or nasal sprays
  • Lotions, gels, or creams (topical steroids)

Corticosteroids work in the following ways:

  • Mimic the effects of naturally occurring hormones such as "cortisol."Decrease inflammation (a process in which the body's white blood cells and chemicals protect against infection and foreign substances such as bacteria and viruses) and reduce the activity of the immune system. 
  • Decrease the production of chemicals that cause inflammation, thus reducing swelling, heat, redness, and pain.
  • Decrease the response of the immune system to various diseases to reduce symptoms such as swelling and allergic-type reactions.
  • Help control the amount of sodium and fluids in the body, thus keeping the blood pressure under control.
  • In addition, they decrease the amount of sodium that is excreted in the urine.
  • When applied topically, they work by activating natural substances in the skin to reduce swelling, redness, and itching.


Corticosteroids are used in conditions such as:

  • Allergic conditions
  • Acute exacerbations of multiple sclerosis (a potentially disabling disease of the brain and spinal cord)
  • Status asthmaticus (respiratory failure that comes with the worst form of acute severe asthma or an asthma attack)
  • Bronchitis (when the tubes that carry oxygen to the lungs [bronchial tubes] get inflamed and swollen)
  • Addison's disease (a rare but serious adrenal gland disorder in which the body cannot produce two critical hormones, cortisol and aldosterone)
  • Congenital adrenogenital syndrome (a group of inherited disorders that are characterized by enlargement of the adrenal glands, resulting primarily from excessive secretion of androgenic hormones by the adrenal cortex)
  • Cerebral edema (a life-threatening condition that causes fluid to develop in the brain)
  • Ulcerative colitis (a condition that causes irritation and ulcers [open sores] in the large intestine [colon]) 
  • Crohn’s disease (a chronic, or long-term, condition that causes inflammation of the digestive tract)
  • Rheumatoid arthritis (an autoimmune and inflammatory disease that causes joint inflammation and pain)
  • Osteoarthritis (a form of arthritis that features the breakdown and eventual loss of the cartilage of one or more joints)
  • Eye conditions
  • Multiple myeloma (cancer that forms in a type of white blood cells called plasma cells)
  • Nephrotic syndrome (a kidney disorder that causes the body to excrete high levels of protein in urine)
  • Duchenne muscular dystrophy (a progressive disease in which the muscles do not function properly)
  • Eczema (a skin disease that causes the skin to be dry and itchy and to sometimes develop red, scaly rashes)
  • Psoriasis (a skin disease in which red, scaly patches form on some areas of the body) 
  • Shock (a life-threatening condition that occurs when the body is not getting enough blood flow)
  • Tenosynovitis (inflammation of a tendon and its sheath)
  • Peritendinitis (inflammation of the middle third of the tendon that produces pain, swelling, and an audible creaking on movement)
  • Bursitis (inflammation or irritation of small, fluid-filled sacs [bursa sac])
  • Giant cell arteritis (an inflammation of the lining of the arteries)
  • Idiopathic thrombocytopenic purpura (an immune disorder that can lead to easy or excessive bruising and bleeding)
  • Advanced pulmonary/extrapulmonary tuberculosis (contagious infection caused by a bacterium called Mycobacterium tuberculosis)
  • Autoimmune hepatitis (a liver inflammation that occurs when the body's immune system attacks liver cells)
  • Dermatoses (skin defect or lesion on the skin)
  • Nasal polyps (soft, painless, noncancerous growths on the lining of nasal passages or sinuses)
  • COVID-19 (NIH guidelines recommend corticosteroids to reduce mortality in hospitalized patients with COVID-19 disease who are receiving either invasive mechanical ventilation or oxygen alone, but not among those receiving no respiratory support)


Some of the common side effects include:

  • Diarrhea
  • Nausea
  • Vomiting
  • Stomach upset
  • Headache
  • Joint/muscle pain
  • Heartburn
  • Weakness
  • Abdominal pain

Other rare side effects include:

  • Dizziness (feeling faint, weak, or unsteady)
  • Weight gain
  • Restlessness
  • Depression
  • Insomnia (trouble falling and/or staying asleep)
  • Anxiety
  • Irregular or absent menstrual periods
  • Swollen face, lower legs, or ankles
  • Black or tarry stools
  • Increased sweating
  • Acne
  • Folliculitis (a common skin condition in which hair follicles become inflamed)
  • Increased hair growth
  • Thinning and easy bruising of the skin
  • Hypertension (high blood pressure)
  • Unusual tiredness

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.


Generic and brand names of corticosteroids include:

References oral/article.htm#what_are_corticosteroids_what_is_the_mechanism_of_action_how_do_they_work

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